scholarly journals Corpus luteum development and its morphology after aspiration of a preovulatory follicle is related to size and steroid content of the follicle in dairy cows

2013 ◽  
Vol 58 (No. 4) ◽  
pp. 221-229 ◽  
Author(s):  
A. Vernunft ◽  
JM Weitzel ◽  
T. Viergutz
Keyword(s):  
Dairy Cows ◽  
Corpus Luteum ◽  
Cross Section ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Cross Section Area ◽  
Section Area ◽  
Preovulatory Follicles ◽  
Luteal Tissue ◽  
Follicle Aspiration

Secretion of adequate levels of progesterone from a proper corpus luteum (CL), which develops out of the cells of a healthy preovulatory follicle, is a key-factor for establishment of a pregnancy. The aim of this study was to investigate the relationship between morphological and secretory characteristics of preovulatory follicles and their corresponding corpus luteum with regard to the post-partum period in high-yielding dairy cows. Therefore, ultrasound-guided aspirations of preovulatory follicles were performed repeatedly, using 20 first lactating cows between 26 and 121 days after parturition. Heat was induced with a PGF analogon followed by administration of a GnRH analogon. The dominant follicle was aspirated 21 h after administration of the GnRH analogon. The diameters of the follicles were estimated at aspiration and the morphology of the resulting luteal tissue was examined on day 14 after follicle aspiration using ultrasonographic examinations. Concentrations of progesterone (P<sub>4</sub>) and 17-beta-oestradiol (E<sub>2</sub>) were determined in the follicular fluids (FF) and P<sub>4</sub> concentration was estimated at the time of CL examination in plasma. A CL development occurred in 82% after dominant follicle aspiration. The interval of time between parturition and follicle aspiration did not affect the investigated variables. The diameter of the aspirated preovulatory follicle was positively correlated to the cross-section area of the developed luteal tissue (R = 0.60; P &lt; 0.01) as well as to the plasma P<sub>4</sub> concentration on day 14 after follicle aspiration (R = 0.47; P&nbsp;&lt; 0.05). Also, E<sub>2</sub> concentrations in FF were positively correlated to cross-section area of the luteal tissue (R = 0.54; P &lt; 0.05). Comparing the FF of the follicles that gave rise to a CL after aspiration to follicles that did not, both types had comparable P<sub>4</sub>, but the former type harboured higher E<sub>2</sub> concentrations. In conclusion, preovulatory follicle diameter as well as steroid concentrations in the follicular fluid could be used prospectively to identify cows which will have well-developed CLs and high plasma P<sub>4</sub> levels later. On the other hand, CL development after follicle aspiration can be used as a retrospective quality parameter of dominant follicles. These results will help to identify suitable animals for breeding or recipients for embryo transfer.&nbsp;&nbsp;&nbsp; &nbsp;

179 CORPUS LUTEUM DEVELOPMENT AFTER FOLLICLE ASPIRATION IS RELATED TO CHARACTERISTICS OF THE ASPIRATED FOLLICLE IN DAIRY COWS

2013 ◽  
Vol 25 (1) ◽  
pp. 238
Author(s):  
A. Vernunft ◽  
J. M. Weitzel ◽  
T. Viergutz
Keyword(s):  
Corpus Luteum ◽  
Cross Section ◽  
Quality Parameter ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Cross Section Area ◽  
Section Area ◽  
Luteal Tissue ◽  
The Cross ◽  
Follicle Aspiration

The aim of this study was to investigate whether morphology or function of a corpus luteum (CL), which developed after an aspiration of a preovulatory follicle, is related to follicular characteristics such as size or steroid content. If so, CL morphology or function could be used as a retrospective quality parameter for the aspirated follicle or the follicular characteristics as a prospective parameter for the quality of the developing CL. Therefore, 44 aspiration sessions were performed using 18 cows between 26 and 121 days after parturition during the first lactation. Heat was induced in mid-dioestrus with Cloprostenol. A GnRH analogon (Depherelin) were administrated 54 h later. The dominant follicle was aspirated 21 h after administration of the GnRH analogue. The diameter of the dominant follicle at aspiration and the cross-section area of the resulting luteal tissue 14 days later were measured by ultrasound. Concentrations of progesterone (P4) and 17-β-oestradiol (E2) in blood and follicular fluid (FF) were determined by H3-RIA. A CL development occurred in 82% of aspiration sessions after aspirating the dominant follicles. The interval of time between parturition and follicle aspiration did not affect variables investigated. As expected, cross-section area of the luteal tissue was positively correlated with plasma P4 concentration on Day 14 after follicle aspiration (r = 0.54; P < 0.01). The diameter of the aspirated follicle was positively correlated with the plasma P4 concentration on Day 14 after follicle aspiration (r = 0.52; P = 0.02), but the diameter was not correlated with the cross-section. Comparing the FF of follicles that originated a CL after aspiration with follicles that did not, both types had comparable P4 concentrations (578 ± 79 ng mL–1 v. 398 ± 84 ng mL–1; P = 0.2), but the former type presented higher E2 concentrations (206 ± 23 ng mL–1 v. 64 ± 29 ng mL–1, P < 0.01) compared with the latter. The P4 concentrations in FF of follicles that originated a CL after aspiration were positively related to cross-section area of the CL (r = 0.48; P = 0.04), but neither P4 nor E2 concentrations in the FF of preovulatory follicles could be used as a predictor for the plasma P4 concentration at day 14. In conclusion, CL development after follicle aspiration can be used as a retrospective quality parameter of aspirated dominant follicles. Preovulatory follicle diameter as well as cross-section area of the luteal tissue could be used prospectively to identify cows with high plasma P4 levels, and this may help to identify suitable recipients for embryo transfer. This study was supported by the German Research Foundation (DFG WE 2458/7-2).

176 BLOOD FLOW TO THE CORPUS LUTEUM AND PREOVULATORY FOLLICLE AFTER OVULATION INDUCTION DURING FIRST VERSUS SECOND WAVE IN WATER BUFFALO

2015 ◽  
Vol 27 (1) ◽  
pp. 179
Author(s):  
S. Caunce ◽  
D. Dadarwal ◽  
P. S. Brar ◽  
J. Singh
Keyword(s):  
Blood Flow ◽  
Corpus Luteum ◽  
Prostaglandin F2α ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Flow Area ◽  
Vascular Area ◽  
Preovulatory Follicles ◽  
Luteal Tissue ◽  
Second Wave

The objective of the study was to compare the blood flow to the corpus luteum (CL) and the preovulatory follicle in dairy buffalo (Bubalus bubalis) when ovulation was induced during the first (low to increasing progesterone levels) versus the second (luteal progesterone levels) follicular wave. We hypothesised that the wall of the first-wave dominant follicle will be less vascular compared with that of the second-wave follicle. The study was conducted during the summer months in Punjab, India. Ovulation was synchronized with prostaglandin F2α (PGF) IM followed by gonadotropin-releasing hormone (GnRH) IM 48 h later (Day 0) and buffaloes were randomised to first wave (FW; n = 6) and second wave (SW; n = 7) groups. FW group was given PGF on Days 6.5 and 7, and GnRH on Day 9.5 followed by AI (14–16 h after GnRH). The SW group was given GnRH on Day 7 (to induce ovulation of first-wave dominant follicle without luteolysis and synchronous emergence of next wave), PGF on Days 13.5 and 14, GnRH on Day 16.5 followed by artificial insemination. Transrectal colour Doppler ultrasonography (MyLab5 Vetwith 7.5 MHz transducer, Esaote S.p.A, Genoa, Italy) was performed daily and 20-s cineloops of each ovary were recorded under standardized gain controls. Images from the cineloops were processed using Fiji (ImageJ, National Institutes of Health, Bethesda, MD, USA) to calculate the area of blood flow (coloured area = vascular area, grey scale area = tissue area, and their ratio) for the preovulatory follicle (on the day before ovulation) and luteal tissue (on the day of PGF injection and 4 days post-ovulation). Data were analysed by t-test from the animals that ovulated one day before (n = 3) or the day of AI (n = 6) and had a functional CL at day 5 post-AI (FW n = 5, SW n = 4). FW follicles ovulated on 8.6 ± 0.3 days from wave emergence compared with SW follicles on 10.0 ± 0.6 days (P < 0.05) but were similar in size (i.e. follicular area on the day before ovulation did not differ between groups; P = 0.5). There was no difference in the blood flow area in the wall of preovulatory follicles (P = 0.4). Vascular area of follicles was strongly correlated with their diameter (r = 0.87). Follicles >13.5 mm in diameter had more blood flow in their wall than smaller follicles (P < 0.01). FW had a tendency (P = 0.07) for smaller luteal area on the day of PGF treatment (FW = 171 ± 24 mm2; SW = 332 ± 81 mm2) and tended (P = 0.06) to have less vascular area in the CL compared to SW group (FW = 30 ± 6 mm2; SW = 67 ± 17 mm2). There was no difference (P = 0.5) between the groups for vascular to CL area ratio. The area of luteal tissue and blood flow to the CL at Day 4 post-ovulation did not differ between the groups (P = 0.4). The diameter of the preovulatory follicle (11.6–15.7 mm) was not correlated with the cross-sectional area of developing CL at Day 4 post-ovulation (r = 0.09). In conclusion, vascularity to preovulatory follicles originating from the first wave v. second wave did not differ and preovulatory follicles ≥13.5 mm were more vascular than smaller follicles. Research was funded by NSERC; the first author was funded by scholarships from WCVM and GADVASU.

Thermoacoustic Shape Optimization of a Subsonic Nozzle

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Alexis Giauque ◽  
Maxime Huet ◽  
Franck Clero ◽  
Sébastien Ducruix ◽  
Franck Richecoeur
Keyword(s):  
Acoustic Emission ◽  
Cross Section ◽  
Source Term ◽  
Combustion Noise ◽  
Noise Emission ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross ◽  
Nozzle Flows ◽  
Subsonic Nozzle

Indirect combustion noise originates from the acceleration of nonuniform temperature or high vorticity regions when convected through a nozzle or a turbine. In a recent contribution (Giauque et al., 2012, “Analytical Analysis of Indirect Combustion Noise in Subcritical Nozzles,” ASME J. Eng. Gas Turbies Power, 134(11), p. 111202) the authors have presented an analytical thermoacoustic model providing the indirect combustion noise generated by a subcritical nozzle when forced with entropy waves. This model explicitly takes into account the effect of the local changes in the cross-section area along the configuration of interest. In this article, the authors introduce this model into an optimization procedure in order to minimize or maximize the thermoacoustic noise emitted by arbitrarily shaped nozzles operating under subsonic conditions. Each component of the complete algorithm is described in detail. The evolution of the cross-section changes are introduced using Bezier's splines, which provide the necessary freedom to actually achieve arbitrary shapes. Bezier's polar coordinates constitute the parameters defining the geometry of a given individual nozzle. Starting from a population of nozzles of random shapes, it is shown that a specifically designed genetic optimization algorithm coupled with the analytical model converges at will toward a quieter or noisier population. As already described by Bloy (Bloy, 1979, “The Pressure Waves Produced by the Convection of Temperature Disturbances in High Subsonic Nozzle Flows,” J. Fluid Mech., 94(3), pp. 465–475), the results therefore confirm the significant dependence of the indirect combustion noise with respect to the shape of the nozzle, even when the operating regime is kept constant. It appears that the quietest nozzle profile evolves almost linearly along its converging and diverging sections, leading to a square evolution of the cross-section area. Providing insight into the underlying physical reason leading to the difference in the noise emission between two extreme individuals, the integral value of the source term of the equation describing the behavior of the acoustic pressure of the nozzle is considered. It is shown that its evolution with the frequency can be related to the global acoustic emission. Strong evidence suggest that the noise emission increases as the source term in the converging and diverging parts less compensate each other. The main result of this article is the definition and proposition of an acoustic emission factor, which can be used as a surrogate to the complex determination of the exact acoustic levels in the nozzle for the thermoacoustic shape optimization of nozzle flows. This acoustic emission factor, which is much faster to compute, only involves the knowledge of the evolution of the cross-section area and the inlet thermodynamic and velocity characteristics to be computed.

An Analytical Method of Analyzing the Heat Conduction for the Unequal Cross-Section Straight Fin

2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song
Keyword(s):  
Heat Conduction ◽  
Cross Section ◽  
Analytical Method ◽  
Thermal Analyses ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Calculation Results ◽  
The Cross ◽  
Analytical Expressions

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.

Rotational Temperature Measurement in Multicomponent Gases Using Raman Scattering Spectroscopy

1976 ◽  
Vol 30 (2) ◽  
pp. 179-183 ◽  
Author(s):  
R. S. Hickman ◽  
A. E. Kassem ◽  
L. H. Liang
Keyword(s):  
Temperature Field ◽  
Raman Scattering ◽  
Temperature Measurement ◽  
Cross Section ◽  
Room Temperature ◽  
Rotational Temperature ◽  
Raman Scattering Spectroscopy ◽  
Scattering Experiment ◽  
Cross Section Area ◽  
Section Area

The rotational temperature at pressures near 1 atm and at room temperature has been successfully measured using spectra obtained in an intracavity Raman scattering experiment. The accuracy of the method is sufficient to allow local temperature measurement of multicomponent gases with no disturbance in the temperature field. The advantage of the method lies in the fact that it does not require knowledge of the relative scattering cross-section area of the component gases.

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